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Explanation:
Since the vertical lines are parallel, this means the alternate exterior angles shown are congruent.
Set them equal to each other and solve for x.
15(x+2) = 120
15x+30 = 120
15x = 120-30
15x = 90
x = 90/15
x = 6
Or we could have the steps like this
x+2 = 120/15
x+2 = 8
x = 8-2
answers are in the pictures
x^3 = 64/343
x^3 = 4^3 / 7^3
x = ∛(4^3 / 7^3)
x = ∛4^3 / ∛7^3
x = 4/7